Complete Gas-Phase Proton Micr oaffinity Analysis o f Two Aliphatic Linear Pentaamine Ligands

The proton affinity of a mon obasic neu tral ligand a t ۰ K is de fined as the negative of the electr onic energy difference between HL+ and L together with a correction for differen ce in zero point energies [۱,۲]. For each po lybasic molecule ther e may be several ways for proton ation depen ding on which site is p rotonated. Protonation of different sites will r elease differ ent amounts of energy. Recently we introduce d three new defined pr oton affiniti es for polyb asic molecules in the ga s phase: proton microaffinity, proton macroaffinity and p roton overallaffinity [۳-۵]. We sho wed that there is a good correlation between th e calculated gas-phase proton macroaffinities of some polyamine ligands wit h corresponding proton ation macroconstants in solution[۳]. Herein we want to report a theoretical study on complete gas phase proton microaffinities of two aliphatic linear pentaa mine ligands with formula: NH۲( CH۲)۲NH(C H۲)۲NH(CH ۲)۲NH(CH۲)۲NH۲ (۲۲۲۲-pent); and NH۲( CH۲)۳NH(C H۲)۲NH(CH ۲)۲NH(CH۲)۳NH۲ (۳۲۲۳ -pent).

کلیدواژه ها:

Theoretical Study ، Proto n Microaffinity ، Proton Macro affinity ، Proton Overallaffinity ، Li near Pentaamines